Wheel with Flexible Wide-Body Spokes

ABSTRACT

A wheel with flexible spokes, including a rim and hub, and spokes between the rim and hub made of fibrous material that causes the spokes to be both lighter in weight and stronger than comparable steel spokes. The spokes are also flexible and resilient such that they can bend while retaining their integrity and strength.

RELATED APPLICATIONS

This application is a divisional of U.S. Utility Patent Application Ser.No. 13/487,253 entitled “Wheel With Flexible Wider Body Spokes” filedJun. 4, 2012, and currently co-pending,

FIELD OF INVENTION

The present invention is directed to vehicular wheels havinghigh-strength and light-weight spokes, particularly bicycle, motorcycle,and wheelchair wheels.

BACKGROUND OF INVENTION

The most common construction for bicycle wheels includes spokes made ofstainless steel or other metal. While stainless steel is strong, it isalso heavy. Therefore, the spokes must be made as thin as possible tomake them as light as possible. However, the thinner the spoke, the lessstrength it has. The thicker the spoke, the stronger it is. Therefore,in making spokes of steel, there is a tradeoff between making the spokesstrong and making them lightweight. Thus, there is a need for a wheelwith spokes that can be both lightweight and strong without having todeal with this tradeoff between the two. Another problem with steelspokes is that, if they are bent, they weaken and ultimately fail suchthat they must be replaced if bent.

One solution to this problem was presented in U.S. Pat. No. 5,110,190which issued to Harold Johnson on May 5, 1992, for an invention entitled“High Modulus Multifilament Spokes And Method” (hereinafter the “'190patent”). The '190 patent is fully incorporated herein by thisreference. The '190 patent discloses a high modulus multifilamentnon-rigid and rigid wheel spoke that includes a fiber mid-portionbetween a first and second end having attachment members affixedthereto. The '190 patent also discloses methods of supporting a hubwithin a wheel rim by means of a plurality of spokes or by means ofcontinuous lengths of spokes.

While the device presented in the '190 patent clearly made advancementsover the state of the art at that time, the device nevertheless has itsshortcomings. For instance, the small diameter of the filament spokesrequires that the spokes be maintained in a substantially axialarrangement with its connectors. This, unfortunately, makes themanufacturing of wheels incorporating the '190 technology more difficultdue to the of off-axis tension.

Specifically, even though the spokes of the '190 patent are orders ofmagnitude stronger than their metallic counterparts, the strength of the'190 spokes is slightly decreased from its maximum strength due to thebend in the spokes as they leave the wheel rim when installed in awheel. U.S. Pat. No. 6,036,281 which issued on Mar. 14, 2000, to RichardCampbell and entitled “Low Rotational Mass Bicycle Wheel System”(hereinafter the '281 patent), disclosed a bicycle wheel system havingspokes extending radially from hub to spoke. The spokes are providedwith fillings at its rim end which are constructed with minimal mass andfillings at the hub end which allow adjustment of the tension of thespoke. The spokes are constructed of a bundle of liquid crystal fibershaving no significant creep surrounded by an extruded plastic jacket.

While the spoke presented in the '281 patent certainly represents amilestone in bicycle wheel technology and light-weight wheelmanufacturing, it nevertheless has its challenges with implementation.First of all, there are manufacturing challenges in keeping the spokesaligned with their connectors. In narrow-width wheel applications, thedevice disclosed in the '281 are difficult to install as the alignmentis important. This alignment results in increased assembly costs andoverall product costs.

The present invention resolves these problems by providing spokes thatare both lighter in weight than steel and significantly stronger thansteel, and that are flexible such that they can bend without sufferingdamage. Moreover, due to their significant strength and durability,fewer numbers of spokes are required on wheels while still providing alightweight wheel with superior strength.

SUMMARY OF THE INVENTION

The wheel with flexible wide-body spokes of the present inventionprovides the aforementioned advantages by providing a wheel including arim and hub, and spokes between the rim and hub made of fibrous materialthat causes the spokes to be both lighter in weight and stronger thancomparable steel spokes. The spokes are also flexible and resilient suchthat they can bend while retaining their integrity and strength.

BRIEF DESCRIPTION OF DRAWINGS

The aforementioned and other advantages of the wheel with flexiblespokes of the present invention will become more apparent to thoseskilled in the art upon making a thorough review and study of thefollowing detailed description of the invention when reviewed inconjunction with the drawings in which like references numerals refer tolike parts, and wherein:

FIG. 1 is a side view of a first preferred embodiment of the wheel withflexible spokes of the present invention, showing the rim, hub, spokesbetween rim and hub, tubes attaching each spoke to the rim, and anchorsattaching each spoke to the hub;

FIG. 2 is a rear detail view of the first preferred embodiment of thewheel with flexible spokes of the present invention, showing the hub,the angle between spokes on the left side of the wheel and spokes on theright side of the wheel, and the angle of the hub surface at the pointof attachment of each spoke to the hub;

FIG. 3 is a cross-sectional view of the first preferred embodiment ofthe wheel with flexible spokes of the present invention, taken acrossline 3-3 of FIG. 1, showing cross-sectional portions of the rim and hub,and showing how each tube attaches each spoke to the rim via a nipple inthe rim, and how each anchor attaches each spoke to the hub;

FIG. 4 is a cross-sectional view of the first preferred embodiment ofthe wheel with flexible spokes of the present invention, taken acrossline 4-4 of FIG. 1, showing a cross-sectional view of the fibers andjacket of one of the spokes; and

FIG. 5 is a cross-sectional view of the first preferred embodiment ofthe wheel with flexible spokes of the present invention showingcross-sectional portions of the rim and hub, and showing how each tube,once attached to the rim, would extent away at an angle from the nipplein the rim.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a side view of a first preferred embodiment of thewheel with flexible spokes of the present invention is shown andgenerally designated 100. In FIG. 1, the side of wheel 100 facing theviewer can be referred to as the right side of the wheel 100. The sideof wheel 100 opposite the right side can be referred to as the left &deof the wheel 100. The wheel 100 has a wheel axis 104, and a rim 110which has an inner perimeter 112 and an outer perimeter 114.

Still referring to FIG. 1, with reference to FIG. 3, distributedsymmetrically along inner perimeter 112 are spoke holes 120. Each spokehole 120 has a spoke hole width 122. Along the outer perimeter 114 arenipple access holes 124 (not visible in FIG. 1), one nipple access hole124 adjacent each spoke hole 120, Wheel 100 further includes a hub 130having a right flange 132 and a left flange 134 (not visible, behindright flange 132). Each flange 132 and 134 has an inner surface 136 andan outer surface 138. In each flange 132 and 134 are flange holes 140,each flange hole 140 corresponding to a unique spoke hole 120. Eachflange hole 140 has an inner opening 142 in the corresponding innersurface 136, and an outer opening 144 in the corresponding outer surface138. Hub 130 also has a barrel 148 which receives an axle of a bicycle.

Wheel 100 further includes non-rigid spoke members, or spokes 150. Eachspoke 150 has non-rigid fibers 152 (not visible this Figure) covered bya jacket 154 having an inner diameter 156 (not visible) and an outerdiameter 158 which is also the width 158 of spoke 150. Each spoke 150has a length 160. Fibers 152 are substantially continuous along thelength 160 of spoke 150. Alternatively, one or more of fibers 152 may beless than continuous along the length of spoke 150.

Each spoke 150 has an inner end 162 adjacent hub 130, and an outer end164 adjacent rim 110. Each spoke 150 has a tube 170 about its outer end164, and each tube 170 is formed with a tapered bore 171 opening awayfrom the midpoint of the spoke. Each tube 170 is affixed to itscorresponding outer end 164 by inserting the fibers 152 into the tube,and filling the tube with epoxy 175. Once hardened, the epoxy 175 andfibers 152 form a wedge within the tapered bore 171 such that anytension on the spoke draws the hardened wedge against the taper therebysecuring the fiber within the tube. Alternatively, tube 170 may beaffixed to outer end 164 by any other material of similar strength.

Tube 170 may be equipped with a hexagonal, reinforced head 165 whichprovides for added strength at the hub-end of the tube 170. This ishelpful in preventing breakage for an non-axial tension on spoke 150,and facilitates the tightening of spoke 150.

Each tube 170 has a tube axis 172 and external spoke threads 174. Eachspoke 150 also has an anchor (or eyelet or ferrule) 180 about its innerend 162. Each anchor 180 is formed with a tapered bore 181 opening awayfrom the midpoint of the spoke. Each anchor 180 is affixed to itscorresponding inner end 162 by inserting the fibers into the anchor, andfilling the tapered bore 181 with epoxy 163. Once hardened, the epoxyand fibers form a wedge within the tapered bore 181 formed in the anchor180 such that any tension on the spoke draws the hardened wedge againstthe taper thereby securing the fiber 150 within the anchor 180.Alternatively, anchor 180 may be affixed to inner end 162 by any othermaterial of similar strength.

Each flange hole 140 is wider than spoke 150 but narrower than anchor180, such that tube 170 about outer end 164 can be passed into inneropening 142 and out of outer opening 144, and such that the rest ofspoke 150 can then be passed through flange hole 140 until anchor 180comes into contact with inner surface 136 around inner opening 142,which causes inner end 162 to be retained in flange hole 140 by anchor180.

Wheel 100 also includes nipples 190. One nipple 190 is shown in FIG. 1in broken line, inside rim 110, There is a nipple 190 between each spokehole 120 and its corresponding nipple access hole 124. Each nipple 190has a nipple opening 192, nipple threads 194 inside nipple opening 192,a collar 196, and a nipple head 198. Once each spoke 150 is passedthrough flange hole 140 until anchor 180 comes into contact with innersurface 136 around inner opening 142, tube 170 is positioned andthreaded into the corresponding nipple 190 via inter-engagement of spokethreads 174 with nipple threads 194. This causes tube 170 to be retainedin nipple 190 such that tube axis 172 is perpendicular to wheel axis 104(shown in FIG. 1). The retention of tube 170 in nipple 190, and of innerend 162 in flange hole 140 by anchor 180, causes spoke 150 to be heldtaut between rim 110 and hub 130.

FIG. 1 shows eight (8) spokes 150 attached to right flange 132, andeight (8) spokes 150 attached to left flange 134 (not visible, behindright flange 132), for a total of sixteen (16) spokes 150. Wheel 100 mayalternatively have more or fewer than sixteen (16) spokes 150, Forexample, wheel 100 may have twelve (12) spokes 150, six (6) spokes 150attached to each of flanges 132 and 134. While it is also possible tohave different numbers of spokes 150 attached to each of flanges 132 and134, having the same number of spokes attached to each of flanges 132and 134 balances the load on the flanges 132 and 134.

FIG. 2 is a rear view of hub 130. FIG. 2 shows the angle that one of thespokes 150 is attached to right flange 132, and the angle that one ofthe spokes 150 is attached to left flange 134. In FIG. 2, the right sideof wheel 100 is on the right side of FIG. 2, and the left side of wheel100 is on the left side of FIG. 2. Broken line 230 in FIG. 2 representsa plane 230 that bisects wheel 100 between the right side and left sideof wheel 100. Plane 230 is perpendicular to wheel axis 104. Each outersurface 138 has the shape of a conical section that has an angle 240 towheel axis 104. Each spoke 150 extends perpendicularly from thecorresponding outer surface 138. Therefore, each spoke 150 extends fromouter surface 138 at an angle 250 to plane 230. This means that themagnitude of angle 260 between spoke 150 attached to right flange 132and spoke 150 attached to left flange 134, is twice the magnitude ofangle 250.

FIG. 3 shows a partial cross-sectional detail view of a spoke 150 withits inner end 162 retained in flange hole 140 by anchor 180, and tube170 about to be received in nipple 190 in rim 110. FIG. 3 shows hownipple 190 is retained in spoke hole 120. Spoke hole width 122 allowsthe portion of nipple 190 around nipple opening 192 to pass throughspoke hole 120, but does not allow collar 196 to pass through spoke hole120, such that nipple is retained in spoke hole 120 by the tension ofspoke 150 on nipple 190 once tube 170 is threaded into nipple 190. FIG.3 also shows spoke threads 174 which inter-engage with nipple threads194 to thread tube 170 into nipple 190. With tube 170 retained in nipple190, tube axis 172 is perpendicular to wheel axis 104 (not shown) andintersects the corresponding spoke hole 120. Spoke holes 120 lie inplane 230. While spoke holes 120 may alternatively be adjacent plane230, spoke holes 120 being in plane 230 causes the forces of spokes 150to be placed on rim 110 where plane 230 intersects rim 110, which is themiddle of the inner perimeter 112 of rim 110. With spoke holes 120 inplane 230, and each tube 170 received in the corresponding nipple 190,tube axis 172 also lies in plane 230.

In FIG. 3, tube axis 172 coincides with the broken fine representingplane 230. However, because each spoke 150 extends at angle 250 to plane230, each spoke 150 extends from its tube 170 at angle 250 to tube axis172. This means that there is a bend in spoke 150 at an angle 250 at thepoint 320 where spoke 150 protrudes from tube 170. With steel spokes,such a bend would weaken the spoke and ultimately cause the spoke tofail. However, with spokes 150, such a bend does not damage spokes 150,because fibers 152 are flexible and resilient yet strong such thatspokes 150 retain their integrity and strength even when bent undertension in the manner described. Therefore, spokes 150 can bend withoutweakening or failing. Furthermore, each of spokes 150 is three times asstrong, and weighs half as much, as a steel spoke that would otherwisebe used in its place. This allows the width 158 of each of spokes 150 tobe greater than that of a steel spoke that would be used in its place.In the alternative, the width 158 of each spoke 150 may be less than orequal to the width of a steel spoke that would be used in its place; thestrength of each of spokes 150 may be greater or less than three timesthat of a steel spoke that would be used in its place; and the weight ofeach of spokes 150 may be greater or less than half that of a steelspoke that would be used in its place.

Rim 110, hub 130, tube 170, anchor 180 and nipple 190, in a preferredembodiment, are made of aluminum. Alternatively, any of rim 110, hub130, tube 170, anchor 180 or nipple 190 may be made of any othermaterial of comparable strength. In a preferred embodiment of thepresent invention, fibers 152 are a bundle of thermotropic liquidcrystal fibers that exhibit high strength, low creep, and weatherresistance. For instance, the fibers could be a PBO fiber such asZylon®, a strong yet lightweight fiber, available from Toyobo.Alternatively, fibers 152 may be made of any other material havingcomparable weight and strength. Jacket 154 is made of Rilsan®, ahigh-performance polyamide. Alternatively, jacket 154 may be made of anyother material having comparable weight and strength. Each nipple accesshole 124 allows access to nipple head 198 so that it can be turned tofacilitate the threading of nipple 190 onto tube 170. For instance, ahexagonal head nut-driver may be positioned over nipple 190 and rotatedto tighten spoke 150 in place.

FIG. 4 shows a cross-sectional detail view of the inside of a spoke 150,showing the fibers 152, and inner diameter 156 of jacket 154. Fibers 152are gathered in forty-four (44) bundles 410 of nine-hundred ninety-six(996) filaments each bundle, for a total of 43,824 filaments in spoke150. This great number of filaments is one factor contributing to thegreat strength of spoke 150, while minimizing the weight of spoke 150.Spoke 150 has a breaking strength of 3,600 pounds. Alternatively, thenumber of bundles 410 may be greater or less than 44; the number offilaments in each bundle 410 may be greater or less than 996; and thebreaking strength of spoke 150 may be greater or less than 3,600 pounds.

Referring to FIG. 5, a cross-sectional view of the first preferredembodiment of the wheel with flexible spokes of the present inventionshowing cross-sectional portions of the rim and hub is shown, As can beappreciated from FIG. 5, the width of rim 110 is just slightly widerthan the width of nipple 190. As a result, it is necessary that thenipple be aligned so that the tube extends radically inward from rim110. Because of this positioning, it is important that spoke 150 beflexible as it leaves tube 190 so as to accommodate angle 250 withoutany decrease in strength and durability. Due to the number of fiberstrands contained within spoke 150, there is no noticeable decrease instrength despite the off-axis tension.

When tension is applied to spoke 150, collar 196 strikes the insidesurface of rim 110 and maintains the nipple, and corresponding sleeve,in its perpendicular arrangement.

While the wheel with flexible spokes of the present invention as hereinshown and disclosed in detail is fully capable of obtaining the objectsand providing the advantages herein before stated, it is to beunderstood that it is merely illustrative of preferred and alternativeembodiments of the invention and that no limitations are intended to thedetails of construction or design herein shown other than as describedin the appended claims.

I claim:
 1. A flexible wide-body spoke, comprising: a flexible shaftcomprising a non-rigid fiber material covered by a jacket having a firstend and a second end; an anchor formed with a bore to receive said firstend of said flexible shaft and said flexible shaft extends through saidanchor, wherein said anchor is configured to be received by a hub; atube having a tube axis and formed with a bore to receive said secondend of said flexible shaft, wherein said flexible mid-portion extendsthrough said tube; and a nipple configured to be received by a rim,wherein said tube is secured to said nipple; and wherein said flexibleshaft protrudes from said anchor at a first spoke angle and saidflexible shaft protrudes from said tube at a second spoke angle whensaid anchor is secured to said hub and said nipple is secured to saidrim.